The field of the invention is closed canisters holding light waveguide splice trays.
When light waveguide cables must be spliced in an area which is not environmentally protected, a heavy duty canister (splice closure) is used. Although the prior art discloses such canisters with end caps at both ends for cable entry, it is now preferred to use canisters with only one end cap so that potential environmental exposure will be minimized. The canister holds a splice tray in which optical fibers from at least two different cables are spliced together.
Because water will eventually impair or terminate proper performance of light waveguide fibers, the splice tray area must be protected from contact with water. To accomplish this, the end cap area where the light waveguide cables enter the canister must be sealed from water entry. This protection may be afforded through the use of tapes, pastes, or gels.
The use of a water impermeable gel immediately inside the end cap gives an important secondary means of preventing water entry to the splicing area. One disadvantage of using a gel, however, is that such gels are messy to work with, particularly if the gel is allowed to be present in the splicing area.
AT&T's Lightguide closure employs the use of a gel immediately facing the end cap of the light waveguide canister. A wrapper is placed around the gel to keep the gel separated from the rest of the contents of the splice closure. Use of the wrapper can be inconvenient, however, and either additional sealants such as 0-rings must be used, in order to prevent water from migrating between the wrapper and the interior surface of the container.
If a waterblocking gel is used immediately inside the container end cap, the partial vacuum which results when the end cap is removed can make it difficult to remove the closure end cap.
It is believed that the state of the art would be improved if a closure could be provided which allowed the use of a waterblocking gel immediately inside the closure end cap, which could completely block the access of water but allow access of light waveguide buffer tubes to the splice tray area, yet which does not require the use of a wrapper and still allows removal of the end cap without a great deal of effort.